Aptly subtitled "..and all about them", the book
covers the topic from basic explanation of
electricity and electromagnetism, construction and
care of batteries, creation of coils and armatures
through wiring and troubleshooting.

The book surveys a wide range of signalling devices, and illustrates them clearly with almost
a hundred sharp, detailed lithographs, with an
addendum in the revised edition on two new devices:
the dry cell and the batteryless magneto bell.

The book is a fascinating snapshot of the use of electricity in a time when you had to make your
own, generally using primary (nonrechargeable)
battery chemistry. The use of the term "recipe"
with regard to primary cell construction is a
delicious reminder that powerful and mature technologies
were once simple enough to be well understood and
easily constructed by a well informed person.